A raster image processor (RIP) is used to convert a page description file (such as a PDF file generated by typesetting software) to a raster image and to output the raster image from a raster imaging device, such as an image setter, a computer-to-plate machine and a digital printer. Any pending print jobs are to be processed through the RIP in order to generate a rasterized image lattice corresponding to each page (hereafter referred to as a page lattice).
A printing controller is provided on a host computer to read the page lattices of the printing jobs from a hard disk and to send printing configuration parameters, control commands, and printing data in order to control the printing process.
A digital control system (DCS) is configured to receive the commands and printing data from the host computer and to drive a spray nozzle of the printer to print in accordance with the commands.
A printing process of an inkjet digital printer includes typesetting the pending print jobs by typesetting software, rasterizing the pending print jobs through the RIP and generating the page lattice available to the inkjet printer. Furthermore, the process further includes receiving the page lattice by the printing controller of the host computer, sending by the controller the received page lattice to the DCS of the inkjet printer and sending by the DCS the page lattice to the spray nozzle to print.
The printing data is sent to the DCS in pages, and thus the printing controller prepares the page lattice in pages. As shown in FIG. 1, the printing data of one page are sent to the DCS after they are prepared.
One of primary uses for double-sided printing with two colors is for printing certain government documents which only need black and red colors, but both sides of a printing stock need to be printed.
In the prior art, a printing process of a double-sided printing with two colors includes: dividing the pending print jobs into odd and even pages; preparing, by the printing controller, page lattices of the odd pages; and sending the page lattices of the odd pages to the DCS. Rectos of the printing stocks are passed through former two colors of the spray nozzle, and the DCS controls the nozzle to print the data of the odd pages on the rectos. Then, the printing stocks are passed through a turnover mechanism. After the printing stocks are turned over, versos of the printing stocks are passed through latter two colors of the spray nozzle. The printing controller sends the page lattice of the even pages to the DCS, and the DCS controls the nozzle to print the data of the even pages on the versos.
In view of the above, for the double-sided printing of the prior art, there is a need to send data of a page for printing the page, which causes a frequent sending of the data and thus reduces the processing efficiency.